Electric-arc-welding system



' a speci 1 UNITED s urt-1s PATENT OFFICE.

HANS FAHNbE, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

ELECTRIC-ARC-WELDING SYSTEM.

Specification ofLctters Patent.

Patented June 15, 1920.

To all whom it may Concern Be it known that I, l-lwxs Fnnxon, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in lllectric-ArelVeldin r Systems, of which the following is f eation.

My invention relates to are welding; systems, and, more particularly, to transfornr ers which may be incorporated in alternatingwurrent welding systems. The prim-.1 ry object of my invention is to provide a simple altornnl .ingcurrent welding system embodyinn characteristics which shall insure the production of strong and homogeneous welds by moderately skilled operators.

It has been found that alternating-current welding systems possess certain desirable features and certain distinct advantages over direct-current welding systems. For example, alternating-current welding terms. may be made lighter in weight and more compact and, therefore, more readily portable than direct-current systen'is. Fur

thermore, alternating-current systems ha ve. been found to be less expensive and are. therefore, desirable from the view point ol economy of installation. llowever, certain diliicnlties have been met, in welding by means of alternatingcurrent, because it is dilticult to establish an arc and this Ilifliculty is believed to exist on account of the reversals of current.

.I. have. founddtlmttlle starting characteristicsoien lteenati entrant system may be considerably improved by employing a. ,relntiyely higl-i voltage (lifting the'period of establishing an arc. Alt io'ugh a relatively high yoltageis desirable to facilitate the establishment of an are, it is not necessary to employ such a high voltage to sustain the are, under operating etiliditiousi One object of my invention, therefore, resides in the provision of a welding system in which a. relatively high voltagemay be utilized during the period of establishing an arc and in which an are-sustaining voltage oi a lower; e s 'hnll be automatically establish-ed a jfter the "n, 0 hits been drawn.

fitn'other objectef my in vention'is to pro- Lvide alternating-current welding; system by connecting a plurality of electrodes to .the'smndary winding of a transformer,

employing'no moving parts or other equipment than the transformer and the necessur electrodes.

'ith these and other objects in iew, my invention will be more fully described and illustrated in the single figure of the drawing which is a diagrammatic view of a, transforim-r having its secondary winding connected to a plurality of electrodes to providean alternating-rurrent welding system, in accordance with my invention.

in practising my invention, I may en1 ploy a transformer comprising: the usual type of laminated ('ore member which, however. is so formed that the )rimary and secondary windings may be adjustably mounted thereon to provide for various values of welding current being drawn from the secondary winding. depending upon the charactor of work to be done. I also employ a. plurality ol' auxiliary windings whichare connected in series with the secondary wind inn' and the electrodes. The auxiliary wind. inns function to supplement the action ofthe seroinla'ry windin; and cause a relatively high voltage to be available across the electrodes. under o|n'n- 'il'('uit conditions, but, when an an has been established between the electrodes and current is flowing in the svrolnlal') winding. the auxiliary windings net as a subilizinpreaetanee in the welding circuit.

In the drawing is shown a transformer ((JIIlPI'lSlI1,1;l eore member having; three legs, 1, 2 and 3, which are connected, at their re: spectivo ends, by straight members izandzo. Additional members (3 land 7 mny he-e ns ployed to connect the legs 1, 2 andjl, adjiu cont one end of the core membenjhus formed, to provide magnetic paths'substantially parallel to the and member 5. ,A,-1 imary winding 8 and a seooinlary vigmin'g 9 may be so mounted upon the. oeutralileg 2 as to be adjustable with respm-ttoleaoh other. The windings 8 and '9 are disposed at the side ol the additional members (i and 7 which comprises the major portion of the core member. A plurality of auxiliary windings 10 may be mounted upon the end member 5, one at each side of the bnntral lop, 2. The auxiliary windings l-tlma, no connected in series with the secondary windinn 9 and in series with one of a; plurality of electrodes 11., the otherelectrodo of which may be eonneeted'to the'seeondury winding 9. A member 12, of substantially E-shape,

may be dis used over the auxiliary windings 10 an be insulated from the member 5 of the'core, as indicated at 13.

In operating the above described welding system, the prnnary and secondar windins may be ad usted relative 'to one other 0 provide for a suitable current being drawn in the secondary circuit. The character of the work governs, to a great extent the' value of the welding current em loyed. It will be appreciated of course, t t, if the prime and secondary windings are separated rom each other, less current will be drawn from the secondary winding than when the windings are closely con led. This istrue because the leaka e rec ance introducel'l between the winchngs, when separated, causes a reduction of-thesecondary current.

In order to perform a welding operation, the primary W11! able supply circuit and the system is then in readiness for o oration. Under-o cn-circuit conditions, or fore an arc has an estab lished between the electrodes 11 the-auxiliary windings 10 increase the voltage which the transformer, which change due to the increased reactence between the primary and the secondary winding.

For example, when no current lows in the secondary winding, the ma etic paths which the flux follows is divided etwecn the members 6 and 7 and the and member 5, but, when current flows in the sccondar winding 9, the flux that reaches the end of e core member,

adjacent the auxiliary windings 10, travels through the additional members 6 and 7 and is, therefore, diverted from the end member 5. The e windings 10, of course, establish a. flux in the magnetic paths at the end of the transformer but this flux does not link with the flux of the secondary winding 9 when current is flowing therein and the auxiliary windings act, under these conditions, merely as reactnnoc in the secondary circuit;

It will be appreciated from the foregoing description that the auxiliary windings 10 are of distinct advantage, both during the period of establishingvahhe arc and under opcrating conditions. on an arc is being established, the auxiliary windings supplement the action of the secondary win mg and make a relatively high voltage available across the electrodes and, after an arc has is connected to a suitrent is flowing in the secondary winding and been established between the tlkl'llfllllh'. [his starting voltage is reduced somewhat by confining the action of the auxiliary windings to a. stnbilizin reactunce. The latter condition is highly esirable in that it Sllllh ilizes the arc and makes the welding operation more easily performed.

It is obvious, from the foregoing don-ription, that I heveprovided a simple alternating-current welding system embodying cvrtain characteristics which facilitate the ostablishment and maintenance of an on: without the employment of moving appuratus or auxiliary equipment. The transformer functions to automatically establish so the above described characteristics. and, therefore, permits-ofthc operator giving his entire attention to the production of good welds. By providing a welding system which is practically contained in a transformer, I have reduced the expense and bulk of the system to a minimum.

Although I have specifically described and shown a transformer embodied in a welding system, it is obvious that minor changcsmay he made therein, without departing; from the spirit or scope of m invention, and T desire, therefore, that no imitations shall be imposed except such as are indicated in the ap dad claims.

claim as my invention 2-- 1. An arc welding system comprising a transformer including a core member, primary and secondar windings mounted thereon, a plurality o auxiliary windings so mounted upon the core member and connected to the secondary winding us to be automatically excluded from the main magnetic circuit when current is flowing in the secomh ary winding and a plurality of electrodes connected in the secondary clwuit.

2. Au arc welding system omnprisiug u.

' transformer including a core memllcr, primary and secondary windings mounted thereon, a pluralityof stationery auxiliar windings so mounted upon the core member and connected to the secondary winding us to be automatically excluded from the main magnetic circuit when current is flowing in the secondary winding and a plurality of; electrodes connected in the secondary circuit.

3. An arcwelding system comprising a, transformer including a core member, primary and secondary windings ndjusmbly mounted thereon, a plurality of stationary auxiliary windings so mounted upon the core member and connected tothe secondary win as to be automatnnlly excluded from c main magnetic circuit when oura plurality of electrodes connected in the secondary circuit.

4. An arc welding transformer comprislug a laminated core member having three legs and members connecting their respective ends, additional members connecting the three legs rid arent one end of the core member thus formed to provide magnetic'paths substantially parallel to the adjacent connecting end member and a plurality of windings mounted upon the end member adjacent the additional members and connected in series with the secondary winding.

5. An arc welding transformer comprising a laminated core member having three legs and members connecting their respective ends, additional members connecting the three legs adjacent one end of the core memher thus formed to roride magnetic paths substantially paralle l to the adjacent connecting end member, a plurality of auxiliary windings mounted upon the end member adjacent the additional members and connected in series with the seconda ry winding and a,

member of substantially E-shape disposed over the auxiliary windings and insulated from the core member.

In testimony whereof I have hereunto subscribed my name this 30th day of Aug, 1919.

HANS FAHNOE. 

